Why An Oil Marinade Might Be Failing Your Tofu
If you've ever tried to marinate tofu for a vegan burger, you've probably used oil in your marinade. It comes from habit: Meat marinades usually benefit from oil since the fats help transfer the flavors onto the meat. Oil is also just an essential component for all sauces, vinaigrettes, and marinades and is the glue that binds loose powdered spices with herbs and liquids. However, such is usually not the case with tofu.
Most of the time, soaking tofu with an oil-based marinade will result in tofu that remains pale and bland throughout, with the sauce merely coating the surface. Although tofu is arguably good on its own as a plain slab of soybean curd, it definitely needs a more potent seasoning in a substitute meat situation. Why doesn't oil marinade work on tofu most of the time? It comes down to the basic rules of chemistry: Oil is fat, and fat is hydrophobic; therefore, the oil and water in the tofu do not work well together.
Tofu is full of water, which makes it a challenge to absorb an oil-based marinade
Unlike meat or fish, tofu has tons of water. In fact, it is mostly made up of water and protein, which means that it needs a liquid-based marinade rather than a fat-based one. Of course, a plethora of marinated tofu recipes call for the use of finishing oils like toasted sesame oil, but this is really only to impart a nutty flavor to the tofu's surface.
Adding oil to a tofu marinade would not truly accomplish the intended role of oil, which is to bring the salts and spices into the flesh of the tofu. Luckily, tofu is incredibly porous and can absorb anything you soak it in, as long as you're not too heavy-handed on the oil. Plus, there are ways to add oil after cooking marinated tofu.
Most marinated tofu recipes call for removing as much water content as you can from the tofu. This makes the tofu denser and meatier, which will allow it to readily take on the flavors of the marinade. You could even air-fry the tofu and dry it out further while giving it a browned exterior.
Marinades made from soy sauce, salt, vinegar, and different spices are the best for tofu steaks and patties. Given a long enough marinating time, around 30 minutes minimum, the tofu will transform into an umami-rich protein. If you want to amp up your marinated tofu, you can always add an oil-based sauce or glaze after you've cooked it.